Generally, in the case of using a compound as an active ingredient of a pharmaceutical product, a single crystal form having certain qualities needs to be stably obtained in a highly reproducible manner. It is also preferable that the resulting single crystal form has superior absorbability.
Meanwhile, (R)—N-(1-(3-(cyclopentyloxy)phenyl)ethyl)-3-((2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)methoxy)propane-1-sulfonamide (hereinafter also referred to as “compound (1)”) represented by formula (1) below:
is described in Patent Document 1 as a compound having deoxyuridine triphosphatase inhibitory activity. Moreover, Patent Document 2 discloses that compound (1) above potentiates the antitumor effects of anticancer agents and is currently under clinical development.
As for the manufacturing method of compound (1), the resulting reaction product was purified by silica gel column chromatography, and the resulting form was a foam (amorphous).
Hence, a crystal form of compound (1), which is preferable as a crystal of a drug substance for use in the production of a pharmaceutical product, is completely unknown.